Boiler



May 1.5, 1934. w. MCGUINEss BOILER Filed March 14, 1933 f/ Mmm .NQ aanLl Figi [Nl/ENTOR hie,

Patented May 15, 1934 UNITED STATES PATENT OFFICE Application March 14,

6 Claims.

The invention relates to new and useful improvements in boilers, andparticularly pertains to water tube boilers adapted for hot waterheating systems and low pressure steam heating systems respectively.

One object of the invention is to provide a novel and improvedconstruction of a combustion chamber with an extended iiue for thecombustion gases, wherein a. complete combustion of all combustiblematter in the combustion gases is obtained and the heat therefrom isutilized to the highest extent for the production of hot water or steamas the case may be, resulting in a very substantial saving of fuel.

A further object of the invention is to provide the boiler with acombustion chamber surrounded by an annular flue through which the hotcombustion gases which leave said combustion chamber are conducted toheat the combustion chamber from the outside before the gases aredischarged into the chimney. In this manner a complete combustion of allcombustible matter in the combustion gases is obtained in a very simpleand eiicient manner.

A still further object of the invention resides in the division of thecurrent of combustion gases which travels through the annular fluesurrounding the combustion chamber. The hotter gases are separated fromthe cooler gases and are passed again through the combustion zoneimmediate above the re, while the cooler gases, containing lesscombustible matter than the hotter gases, are permitted to expand withinthe annular flue just before they are discharged into the chimney.

In the drawing:

Fig. 1 is a vertical cross-section of the boiler, certain portions beingshown as broken away, and

Fig. 2 shows diagrammatically a perspective view of the furnace, thetravel of the combustion lgases being indicated by arrows.

According to the drawing, the boiler of the present invention isprovided with a front wall 5, side walls 6 and 7 a rear wall 8 and a topwall 9. The walls 5, 6, 7 and 8 are connected together at their verticaledges and are mounted on a suitable fundation 10 made from refractorymaterial, fire proof brick, cement, torpedo gravel or the like. Thisfoundation l contains the ash pit 1l and the grate 12 of the boiler, theiront wall of said foundation being provided with the customary draftpanel door 13 which permits access to the ash pit ll and the regulationof the natural draft in the boiler. Within the space conned by thefront, side and rear walls is arranged an inner casing comprising thevertical walls 14, 15, 1 6

1933, Serial No. 660,662

ber 18 which extends around the entire inner casing and is used as aflue through which the combustion gases are conducted before beingdischarged into the chimney. Within the inner casing are arranged thefire box 19, the lower receivers 20 and 21, the upper receiver 22 andthe water tubes 23 connecting the lower receivers with the upperreceiver. The lower portion of the inner casing surrounds the lire box19 into which fuel may be introduced through a. door arranged in theouter front wall and an opening 25 in the front wall 14 of the innercasing. The outer front wall 5 is also provided with a door 26 throughwhich the clinker may be removed from the grate 12.

The upper end of the inner casing is closed by the top wall 9. The sidewall of the inner' casing has near its upper end a longitudinal opening27 through which the hot combustion gases are conducted into the annulargas chamber 18. A baille plate 28 extending along the.

upper horizontal edge of the opening 27 directs the hot gases downwardlyinto the air space between the walls 15 and 6. Within this air space isarranged near the rear end of the same an upwardly extending baie plate29 which completely bridges the distance between the inner wall 15 andthe outer side wall 6 and directs the hot gases forwardly toward thefront of the boiler.

According to Fig. 1 there is arranged in the air space between the frontwall 14 of the inner casing and the outer front wall 5 a partition wall30 which according to Fig. 2 is arranged to the left hand side of theopening in the wall 14 and Vextends. vertically downward from the topwall 9 to a point somewhat below the lower edge of the opening 25. Thisvertical partition is connected with a horizontal partition 31, whichextends along the lower edge of the opening 25 and is then bentvertically upward at 32 at the right hand side of the same to terminatein anv outwardly inclined portion 33.

The partition wall 30, 31, 32, 33 divides the air space between walls 14and 5 into two superposed chambers or flues. VThe hot gases flowing inthe air space between the walls 15 and 6 forwardly are divided by thehorizontal wall portion 31 into two currents. The upper current, whichcontains the hotter gases, is conducted by the partition will into theopening25 in the front wall 14 of the inner casing and thereforere-enters the` combustion zone of the boiler. The lower current, whichcontains cooler gases, is directed past the front of the boiler into theair space between the side walls 7 and 16. This air space extends theentire height of the walls 7 and 16 and permits an expansion of thecombustion gases before they are discharged into the chimney 34. Thechimney 34 is preferably connected with the lower left hand corner (Fig.l) of the air space between the inner rear wall 17 and the outer rearwall 8 as shown at 35. However, the chimney 34 may also be connectedwith the right hand corner of said air space or any other point of saidair space, if this should be desired for any reason. During the travelof the combustion gases from the re box upwardly into the cornbustionchamber and outwardly into the upper end of said annular gas chamber orflue surrounding the entire inner casing, the gases become completelyburned and all their heat is utilized to heat the hot water tube systemwithin the inner casing. Those gases which are relatively hot andcontain still Ian Yappreciable portion of combustible matter are'separated from the cooler gases and are again passed through the'combustion zone. The combustion gases which 'are discharged into thechimney are free of any combustible matter -so that the smoke whichleaves the chimney is absolutely white and is free of soot, coal dust orthe like. In practice it has been found, that the chimney remainsabsolutely cool, which may be considered proof, that the combustiongases 'discharged from the boiler have all their vheat transferre'd toactive heating surfaces.

Referring now to the water tube system 'of the boiler, 'the lowerreceivers 20 'and 21 vare preferably circular in cross-section and arepositioned in the lower left 'and right hand 'corner of the inner`casing, extending horizontally from the 'front toward the rear of theboiler. These yreceiver tubes 20 and 2l project voutwardly from the.front kwall v5 and rear wall 8 respectively fand their `vends Aareiianged and fare closed by removable cover plates which Vfacilitatecleaning of the receivers. The upper receiver' 22 in which the steamseparates `from the water, when the boiler is 'used for a steam or vaporheating system, is yof Y`larger .diameter than .the lower receivers 20vand v2-1 and 'is arranged centrally :in the upper portion of theinnercasin'g, Sjust below the top -wall 9, extending horizontally fromthe front 'toward the rear of the boiler. The ends of said 'upperreceiver l22 extend 'through 'the v'outer front ,and rear walls 5 and I8respectively and are likewise `flanged and 'provided with removablecover `plates 40. Both lower receivers 420 and 21 tare connected withthe 'upper receiver '22'by asseries of water tubes v23 of novelfor-mation and arrangement. The xwater tubes 23in`eachrow1are spaced`from yone another iln longitudinal directionxof vthe receivers, and onerow is lstaggered 'with vrespect Ito the :other row `order that the'upperiportionsiof the water 'tubes `123 lmaybe arrangedin interlinkedrelation as will fbe described presently. lIhe ldistance between eachtwo 1water 4tubes V23 zin each zrow is at :least as large as or largerthan theoutside diameter of one 'water "tube Y23. Since all ywateritubes .23 are 'arranged andbent in similar fmanner, it is vdeemed-suicient "when Aonly fone water :tube is zdescribed inid'eta'il. Thelower vend-of `thezwater tube 23,is

`-w`eldedinto-theuppier 1.wall `of the lower receiver -20"cr21fa`s'thercasezmaybe, and extendsvertically upwardly Aapproximately to :the:height `in which the?upper'edgeofthefopening25V is' located. Thenfthetub'el23 isibentalmostfhorizontallyptoward the opposite side wall ofthe inner casing, when it is bent upwardly and backwardly to form asemicircular bend as shown at 42. The tube 23 eX- tends again almosthorizontally toward the opposite side wall of the inner casing and afterforming another semi-circular bend 43 it is welded into the lower wallof the upper receiver 22. Attention is called to the fact, that theupper end o-f the sinuously bent tubes 23 are connected to the same sideof the upper receiver 22 on which the corresponding lower receiver 20 or21 is 1ocated, in order to facilitate repairs and replacements.Furthermore, it is to be noted, that those tube sections which extendtransversely of the inner casing from one side wall to the other are notarranged absolutely horizontal, but they are positioned somewhatinclined in order to prevent any accumulation lof sediment in theseportions of the water tubes. While I have shown water tubes with twosemi-circular bends, it is, of course, obvious that more `or less bendsmay -be provided, to increase or decrease the heating .sur-face of theboiler. It is also obvious, that instead of connecting each lowerreceiver with one row of water tubes to the upper receiver, I mayarrange two or more rows of water tubes connecting each lower receiverwith the upper receiver. All these modications are within the scope ofmy invention.

In the above described manner, all the water tubes 23 are arranged inclosely nested relation within the inner casing in which the`.combustion of the y'fuel Atakes place. The hotcornbustion gases whichnow upwardly have to pass along and through the slot-like spaces formedbetween the -two .sets of water tubes before leaving the inner casingthrough the opening 27, so -that the water tubes 23 and upper receiver22 a-re `heated very efficiently, speedily and economically.

In addition to the 'twoseries of water tubes 23,

there are provided within the inner casing, .adja- Y' cent the frontwall 14 and rear lwall -17 thereof specially constructed circulatingtubes which .en-

-hance the-.circulationof the water in the boiler and also reinforce theentire watertube system. Each circulating tube comprises va verticaltube section 46connected with its -upper end to the bottom wall oftheupper receiver 22'and having its lower end dividedin two branches 47 and48 which .extend horizontally and then again vertical-downwardly to lbeconnected with their lowerends to the lower receivers 2() and 2lrespectively. Furthermore, the lower -ends of said branch tubes 47 Vand48 `are -connected with lone another by a horizontal tube 49 (Fig. 1')These circulating tubes, Apreferably have a larger diameter than thewater tubes 2-3.

'The other-details of the boiler are conventional. The upper receiverVV22 has at'its ends, in the -top wall thereof Iupwardly extendingfittings 50 which project through the top 4wall Sand are connectedwith-.the endsof a steam or Ahot water header 52. The header 52 isprovided with flanged openings '53 adapted to be connected to a hotwater heating system-or a steam heating system or the like, it beingunderstood that the boiler may be used with feitherone of the -two-heating systems mentioned.

In order vto supply the vboiler with water, one .of the ylower receivers20 or 2l is connected by a pipe 54 witha source-of water supply, -e. g.,a water main. Ablow oif valve is indicated at 55.

While the boiler inthe described embodiment ls provided with a furnaceusing hard or soft :oal 4or other solid fuel, I also .contemplate toequip the vboiler with any .other heating device, as .for instance anoil burner or :a :burner for .ric

ffl

gaseous fuel. Regardless of what kind of a fuel will be used in theoperation of the boiler, there will always be obtained a great saving offuel. Furthermore, the boiler is very compact when assembled andrequires very little space. For the average home it may be completelyassembled at the factory and may be installed very readily andconveniently, as it may be brought in through any average door, so thatit is not necessary to tear down permanent walls or the like in order toinstall the boiler.

Having thus described my invention, what I claim is:

1. In a boiler, a combustion chamber haging vertical front, side andrear walls, means forming an annular flue around the vertical walls ofsaid combustion chamber, one side wall having adjacent its upper end anopening to conduct all of the hot gases from said combustion chamberinto said annular flue, means within said annular flue for deilectingthe gases toward the front wall of said combustion chamber the frontwall having baie means and an opening for returning some of the hotgases traveling within said annular flue to the combustion chamber, adischarge conduit into which the rest of the hot gases is conducted bysaid annular ilue, and tubes within said combustion chamber for heatingthe water of the boiler, said tubes being heated by the hot gases beforethe same are discharged into said annular ue.

2. A boiler including a combustion chamber having vertical front, sideand rear walls and a top wall completely closing the upper end of saidchamber, means forming an annular ue surrounding the outside of thevertical walls of said combustion chamber, said flue having a widthextending the entire height of said vertical walls from the bottomthereof to said top wall, one side wall having adjacent its upper end anopening for conducting all of the hot gases from said combustion chamberinto said annular ue, the front wall having a baiile and an opening forreturning some of the hot gases owing within said annular flue into thecombustion chamber, a discharge conduit into which the rest of the hotgases is conducted by said annular flue, and tubes within saidcombustion chamber for heating the water of the boiler, said tubes beingheated by the hot gases before the same are discharged into said annularue.

3. A boiler including a combustion chamber having a front wall, two sidewalls, a rear wall and a top wall, said combustion chamber beingsurrounded by a casing comprising walls which are parallel to and spacedfrom said front, side and rear wall and covered by said top wall to forman annular flue, one of said side walls having an opening near its upperend for connecting the interior of the combustion chamber with saidflue, the iront wall having a bale and an opening near its center forreturning some of the combustion gases traveling in said iiue into saidcombustion chamber, the rear wall of said casing being provided near itslower edge with an opening for connecting said annular flue with achimney, and tubes within said combustion chamber for heating the waterof the boiler by the combustion gases.

4. A boiler including a combustion chamber having a front wall, two sidewalls, a rear wall and a top wall, said combustion chamber beingarranged within a casing having walls parallel to and spaced from saidfront, side and rear walls, whereby an annular ue is formed having awidth of substantially the entire height of the Walls forming saidcombustion chamber, one of said side walls having adjacent its upper endan opening connecting said combustion chamber with said annular ue, saidfront wall having an opening near its center and means including ahorizontal baille below said opening for dividing the combustion gasestraveling along said annular flue in an upper current and a lowerourrent, said upper current being returned into said combustion chamber,the lower current of gases being conducted by said annular flue t0- wardthe rear wall of said combustion chamber along the outside of the otherside wall of the same, the rear wall of said casing having an openingthrough which the gases are discharged.

5. In a boiler, the combination of a fire box, an upwardly extendingcombustion chamber and boiler tubes completely arranged within saidcombustion chamber, with means forming an annular flue which surroundssaid combustion chamber and into which all of the combustion gases areconducted, said flue being connected with the upper end of saidcombustion chamber, a discharge conduit connected with said annular ueat a point remote from its connection with the combustion chamber, andmeans within said annular ue for returning a part of the combustiongases traveling in said flue into said combustion chamber for repeatedcombustion.

6. In a water tube boiler, the combination of a fire box, an upwardlyextending combustion chamber and a series of water tubes arrangedcompletely within said combustion chamber, with means forming an annularflue which surrounds said combustion chamber and into which all of thecombustion gases are conducted, said flue being connected with the upperend of said combustion chamber and a discharge conduit connected withsaid annular ue adjacent its lower end, the width of said ue beingsubstantially as great as the height of said combustion chamber, so thatthe latter is heated from the outside by the combustion gases travelingin said annular flue in substantially circumferential direction.

WILLIAM MCGUINESS.

